1. Field of the Invention
This invention relates to a clamping apparatus for use in releasably grasping a load to be lifted from two or more sides. It also relates to an adjustable bushing suitable for slidably supporting a translating member, such as a clamping arm of a clamping apparatus.
2. Description of the Related Art
Various clamping apparatuses have been developed for use in lifting loads. Among these clamping apparatuses are ones having a plurality of clamping arms which can releasably grasp a load to be lifted from multiple sides. In some cases, the clamping arms pivot between an open and closed position. In other cases, the clamping arms translate without pivoting along a linear or other path between an open and closed position.
With a clamping apparatus of the type in which clamping arms translate without pivoting, bearings for supporting the clamping arms can wear out over time, and when such wear occurs, it is difficult to guide the clamping arms in a stable manner.
With a clamping apparatus of the type in which the clamping arms pivot between an open and closed position, the angle with respect to the vertical of the contact portions of the clamping arms which contact a load to be lifted may vary significantly as the clamping arms pivot. Therefore, when the clamping apparatus is used to grasp loads having different dimensions, it is difficult to maintain a suitable angle of the contact portions for all of the loads.